Longitudinal Assessment of Tau-Associated Pathology by 18F-THK5351 PET Imaging: A Histological, Biochemical, and Behavioral Study

Several common and debilitating neurodegenerative disorders are characterized by the intracellular accumulation of neurofibrillary tangles (NFTs), which are composed of hyperphosphorylated tau protein. In Alzheimer's disease (AD), NFTs are accompanied by extracellular amyloid-beta (A beta), but primary tauopathy disorders are marked by the accumulation of tau protein alone, including forms of frontotemporal dementia (FTD), corticobasal degeneration (CBD), and progressive supranuclear palsy (PSP), among others. F-18-THK5351 has been reported to bind pathological tau as well as associated reactive astrogliosis. The goal of this study was to validate the ability of the PET tracer F-18-THK5351 to detect early changes in tau-related pathology and its relation to other pathological hallmarks. We demonstrated elevated in vivo F-18-THK5351 PET signaling over time in transgenic P301S tau mice from 8 months that had a positive correlation with histological and biochemical tau changes, as well as motor, memory, and learning impairment. This study indicates that F-18-THK5351 may help fill a critical need to develop PET imaging tracers that detect aberrant tau aggregation and related neuropathology in order to diagnose the onset of tauopathies, gain insights into their underlying pathophysiologies, and to have a reliable biomarker to follow during treatment trials.

Automated summary

This study focused on validating the effectiveness of the PET tracer F-18-THK5351 in detecting early changes in tau-related pathology, showing increased PET signaling over time in transgenic P301S tau mice with positive correlations to histological and biochemical tau changes, as well as motor, memory, and learning impairment. The findings suggest that F-18-THK5351 could be a useful tool in diagnosing tauopathies, understanding their pathophysiologies, and monitoring treatment trials.